Method and apparatus for mitigating interference in femtocell deployments

ABSTRACT

Methods and apparatuses are provided for mitigating interference among access points, and/or devices communicating therewith, in unplanned network deployments. Based on determining that one or more served devices potentially interfere with one or more access points, an inter-frequency handover (IFHO) threshold or data rate can be adjusted for the device to cause IFHO or reduce occurrence of interference, and/or a coverage area can be modified so the device can communicate with one or more other access points to mitigate potential interference. Based on determining interference from one or more devices served by other access points, an access point can switch operating modes to a hybrid or open access point to allow the one or more devices to handover to the access point, and/or can boost downlink transmit power to cause the one or more devices to perform IFHO from the other access points to mitigate potential interference.

CLAIM OF PRIORITY UNDER 35 U.S.C. §119

The present application is a divisional application of U.S. patentapplication Ser. No. 13/170,488 filed on Jun. 28, 2011, titled “Methodand apparatus for mitigating interference in femtocell deployments”which claims the benefit to U.S. Provisional Application No. 61/359,754filed on Jun. 29, 2010, titled “Enhanced uplink interference management”and assigned to the assignee hereof and hereby expressly incorporated byreference herein.

BACKGROUND

Field

The following description relates generally to wireless networkcommunications, and more particularly to mitigating interference infemtocell deployments.

Background

Wireless communication systems are widely deployed to provide varioustypes of communication content such as, for example, voice, data, and soon. Typical wireless communication systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing available system resources (e.g., bandwidth, transmit power, . .. ). Examples of such multiple-access systems may include code divisionmultiple access (CDMA) systems, time division multiple access (TDMA)systems, frequency division multiple access (FDMA) systems, orthogonalfrequency division multiple access (OFDMA) systems, and the like.Additionally, the systems can conform to specifications such as thirdgeneration partnership project (3GPP), 3GPP long term evolution (LTE),ultra mobile broadband (UMB), evolution data optimized (EV-DO), etc.

Generally, wireless multiple-access communication systems maysimultaneously support communication for multiple mobile devices. Eachmobile device may communicate with one or more access points viatransmissions on forward and reverse links. The forward link (ordownlink) refers to the communication link from access points to mobiledevices, and the reverse link (or uplink) refers to the communicationlink from mobile devices to access points. Further, communicationsbetween mobile devices and access points may be established viasingle-input single-output (SISO) systems, multiple-input single-output(MISO) systems, multiple-input multiple-output (MIMO) systems, and soforth. In addition, mobile devices can communicate with other mobiledevices (and/or access points with other access points) in peer-to-peerwireless network configurations.

To supplement conventional base stations, additional restricted accesspoints can be deployed to provide more robust wireless coverage tomobile devices. For example, wireless relay stations and low power basestations (e.g., which can be commonly referred to as Home NodeBs or HomeeNBs, collectively referred to as H(e)NBs, femto access points,femtocells, picocells, microcells, etc.) can be deployed for incrementalcapacity growth, richer user experience, in-building or other specificgeographic coverage, and/or the like. In some configurations, such lowpower base stations can be connected to the Internet via broadbandconnection (e.g., digital subscriber line (DSL) router, cable or othermodem, etc.), which can provide the backhaul link to the mobileoperator's network. Thus, for example, the low power base stations canbe deployed in user homes to provide mobile network access to one ormore devices via the broadband connection.

In this regard, deployment of such low power base stations is unplannedin many cases, and thus the base stations and/or mobile devicescommunicating therewith can cause interference to other low power basestations, macrocell base stations, or other devices in the vicinity.Similarly, devices communicating with a macrocell base station caninterfere with nearby femtocell access points.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In accordance with one or more embodiments and corresponding disclosurethereof, various aspects are described in connection with reducinguplink interference to a femtocell access point from one or more devicescommunicating with a macrocell access point and/or vice versa. In oneexample, an inter-frequency handover (IFHO) threshold can be lowered fora device communicating with the macrocell access point when potentialinterference to the femtocell access point from the device is determinedto exceed a threshold level. In another example, the femtocell accesspoint can switch to a hybrid operating mode once interference from thedevice exceeds a threshold level to facilitate handing the device overto the femtocell access point. In another example, a data rate of thedevice can be limited by the macrocell access point when interferencefrom the device to the femtocell access point exceeds a threshold level;this can result in the device transmitting to the macrocell access pointat a lower power. In yet another example, the femtocell access point canincrease a downlink transmission power, such that interference from thefemtocell access point to the device exceeds the IFHO threshold, andcauses an IFHO of the device from the macrocell access point. In anotherexample, the femtocell access point can reduce interference to macrocellaccess points caused by one or more devices communicating with thefemtocell access point by reducing a coverage area of the femtocell.

According to an example, a method for mitigating interference in awireless network is provided. The method includes determining that aserved device potentially interferes one or more access points andadjusting an inter-frequency handover threshold or a data rate for theserved device based at least in part on the determining.

In another aspect, an apparatus for mitigating interference in awireless network is provided. The apparatus includes at least oneprocessor configured to determine that a served device potentiallyinterferes one or more access points. The at least one processor isfurther configured to adjust an inter-frequency handover threshold or adata rate for the served device based at least in part on thedetermining. The apparatus also includes a memory coupled to the atleast one processor.

In yet another aspect, an apparatus for mitigating interference in awireless network is provided that includes means for determining that aserved device potentially interferes one or more access points. Theapparatus further includes means for adjusting an inter-frequencyhandover threshold or a data rate for the served device based at leastin part on the means for determining determining that the served devicepotentially interferes the one or more access points.

Still, in another aspect, a computer-program product for mitigatinginterference in a wireless network is provided including acomputer-readable medium having code for causing at least one computerto determine that a served device potentially interferes one or moreaccess points. The computer-readable medium further includes code forcausing the at least one computer to adjust an inter-frequency handoverthreshold or a data rate for the served device based at least in part onthe determining.

Moreover, in an aspect, an apparatus for mitigating interference in awireless network is provided that includes an interference determiningcomponent for determining that a served device potentially interferesone or more access points. The apparatus further includes a componentfor adjusting an inter-frequency handover threshold or a data rate forthe served device based at least in part on the interference determiningcomponent determining that the served device potentially interferes theone or more access points.

According to another example, a method for mitigating interference in awireless network is provided including operating in a closed access modeallowing communications with member devices and detecting interferencefrom one or more non-member devices served by one or more access points.The method further includes switching to a hybrid or open access mode toallow communications with the one or more non-member devices based onthe detected interference

In another aspect, an apparatus for mitigating interference in awireless network is provided. The apparatus includes at least oneprocessor configured to advertise a closed access mode allowingcommunications with member devices and detect interference from one ormore non-member devices served by one or more access points. The atleast one processor is further configured to switch to advertise ahybrid or open access mode to allow communications with the one or morenon-member devices based on the detected interference. The apparatusalso includes a memory coupled to the at least one processor.

In yet another aspect, an apparatus for mitigating interference in awireless network is provided that includes means for operating in aclosed access mode allowing communications with member devices. Theapparatus further includes means for detecting interference from one ormore non-member devices served by one or more access points, wherein themeans for operating switches to a hybrid or open access mode to allowcommunications with the one or more non-member devices based on thedetected interference.

Still, in another aspect, a computer-program product for mitigatinginterference in a wireless network is provided including acomputer-readable medium having code for causing at least one computerto advertise a closed access mode allowing communications with memberdevices and code for causing the at least one computer to detectinterference from one or more non-member devices served by one or moreaccess points. The computer-readable medium further includes code forcausing the at least one computer to switch to advertise a hybrid oropen access mode to allow communications with the one or more non-memberdevices based on the detected interference.

Moreover, in an aspect, an apparatus for mitigating interference in awireless network is provided that includes a pathloss receivingcomponent for obtaining an access mode component for operating in aclosed access mode allowing communications with member devices. Theapparatus further includes an interference detecting component fordetecting interference from one or more non-member devices served by oneor more access points, wherein the access mode component switches to ahybrid or open access mode to allow communications with the one or morenon-member devices based on the detected interference.

In another example, a method for mitigating interference in wirelesscommunications is provided including detecting interference from one ormore devices communicating with one or more access points and increasinga downlink transmit power according to a boosting pattern over timebased on detecting the interference.

In another aspect, an apparatus for mitigating interference in wirelesscommunications is provided. The apparatus includes at least oneprocessor configured to detect interference from one or more devicescommunicating with one or more access points. The at least one processoris further configured to increase a downlink transmit power according toa boosting pattern over time based on detecting the interference. Theapparatus also includes a memory coupled to the at least one processor.

In yet another aspect, an apparatus for mitigating interference inwireless communications is provided that includes means for detectinginterference from one or more devices communicating with one or moreaccess points. The apparatus further includes means for increasing adownlink transmit power according to a boosting pattern over time basedon detecting the interference.

Still, in another aspect, a computer-program product for mitigatinginterference in wireless communications is provided including acomputer-readable medium having code for causing at least one computerto detect interference from one or more devices communicating with oneor more access points. The computer-readable medium further includescode for causing the at least one computer to increase a downlinktransmit power according to a boosting pattern over time based ondetecting the interference.

Moreover, in an aspect, an apparatus for mitigating interference inwireless communications is provided that includes an interferencedetecting component for detecting interference from one or more devicescommunicating with one or more access points. The apparatus furtherincludes a downlink transmit component for increasing a downlinktransmit power according to a boosting pattern over time based ondetecting the interference.

According to another example, a method for mitigating interference inwireless communications is provided. The method includes determiningthat a served device potentially interferes one or more access pointsand adjusting a pathloss edge target based at least in part on thedetermining.

In another aspect, an apparatus for mitigating interference in wirelesscommunications is provided. The apparatus includes at least oneprocessor configured to determine that a served device potentiallyinterferes one or more access points. The at least one processor isfurther configured to adjust a pathloss edge target based at least inpart on the determining. The apparatus also includes a memory coupled tothe at least one processor.

In yet another aspect, an apparatus for mitigating interference inwireless communications is provided that includes means for determiningthat a served device potentially interferes one or more access points.The apparatus further includes means for adjusting a pathloss edgetarget based at least in part on the means for determining determiningthat the served device potentially interferes.

Still, in another aspect, a computer-program product for mitigatinginterference in wireless communications is provided including acomputer-readable medium having code for causing at least one computerto determine that a served device potentially interferes one or moreaccess points. The computer-readable medium further includes code forcausing the at least one computer to adjust a pathloss edge target basedat least in part on the determining.

Moreover, in an aspect, an apparatus for mitigating interference inwireless communications is provided that includes an interferencedetermining component for determining that a served device potentiallyinterferes one or more access points. The apparatus further includes apathloss edge target adjusting component for adjusting a pathloss edgetarget based at least in part on the interference determining componentdetermining that the served device potentially interferes.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements, andin which:

FIG. 1 is a block diagram of an example system that facilitatesmitigating interference in a wireless network.

FIG. 2 is a block diagram of an example system for mitigatinginterference caused by one or more served devices.

FIG. 3 is a block diagram of an example system for mitigatinginterference from one or more non-member devices.

FIG. 4 is an example downlink transmit power boosting pattern to causeone or more interfering devices to perform handover.

FIG. 5 is a block diagram of an example system for modifying a coveragearea to mitigate interference in a wireless network.

FIG. 6 is a flow chart of an aspect of an example methodology thatmitigates interference from one or more served devices.

FIG. 7 is a flow chart of an aspect of an example methodology thatmitigates interference by switching access modes.

FIG. 8 is a flow chart of an aspect of an example methodology forboosting a downlink transmit power to mitigate interference.

FIG. 9 is a flow chart of an aspect of an example methodology thatmodifies a coverage area to mitigate device interference to other accesspoints.

FIG. 10 is a block diagram of an example system for mitigatinginterference caused by one or more devices.

FIG. 11 is a block diagram of an example system that causes one or moreinterfering devices to perform handover.

FIG. 12 is a block diagram of an example system that mitigatesinterference by switching access modes.

FIG. 13 is a block diagram of an example system that boosts a downlinktransmit power to mitigate interference.

FIG. 14 is a block diagram of an example system that modifies a coveragearea to mitigate device interference to other access points.

FIG. 15 is a block diagram of an example wireless communication systemin accordance with various aspects set forth herein.

FIG. 16 is an illustration of an example wireless network environmentthat can be employed in conjunction with the various systems and methodsdescribed herein.

FIG. 17 illustrates an example wireless communication system, configuredto support a number of devices, in which the aspects herein can beimplemented.

FIG. 18 is an illustration of an exemplary communication system toenable deployment of femtocells within a network environment.

FIG. 19 illustrates an example of a coverage map having several definedtracking areas.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details.

As described further herein, interference in femtocell deploymentscaused by devices communicating with one or more access points can bemitigated. For example, inter-frequency handover (IFHO) can be triggeredfor a device communicating with a macrocell access point and causing atleast a threshold level of interference to a femtocell access point. Inanother example, a femtocell access point can switch to operate in ahybrid access mode to serve one or more devices interfering with thefemtocell access point. Moreover, for example, a macrocell access pointcan limit a data rate of a device communicating therewith to lowertransmit power of the device and thus mitigate interference to one ormore other access points. In yet another example, a femtocell accesspoint can increase downlink transmission power to cause interference toa device communicating with a macrocell access point to initiate IFHOfor the device. Furthermore, to mitigate interference to a macrocellaccess point, caused by devices communicating with a femtocell accesspoint, the femtocell access point can reduce a coverage area.

As used in this application, the terms “component,” “module,” “system”and the like are intended to include a computer-related entity, such asbut not limited to hardware, firmware, a combination of hardware andsoftware, software, or software in execution. For example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets, such as data from one component interactingwith another component in a local system, distributed system, and/oracross a network such as the Internet with other systems by way of thesignal.

Furthermore, various aspects are described herein in connection with aterminal, which can be a wired terminal or a wireless terminal Aterminal can also be called a system, device, subscriber unit,subscriber station, mobile station, mobile, mobile device, remotestation, remote terminal, access terminal, user terminal, terminal,communication device, user agent, user device, or user equipment (UE). Awireless terminal may be a cellular telephone, a satellite phone, acordless telephone, a Session Initiation Protocol (SIP) phone, awireless local loop (WLL) station, a personal digital assistant (PDA), ahandheld device having wireless connection capability, a computingdevice, or other processing devices connected to a wireless modem.Moreover, various aspects are described herein in connection with a basestation. A base station may be utilized for communicating with wirelessterminal(s) and may also be referred to as an access point, a Node B,evolved Node B (eNB), H(e)NB, or some other terminology.

Moreover, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” That is, unless specified otherwise, or clearfrom the context, the phrase “X employs A or B” is intended to mean anyof the natural inclusive permutations. That is, the phrase “X employs Aor B” is satisfied by any of the following instances: X employs A; Xemploys B; or X employs both A and B. In addition, the articles “a” and“an” as used in this application and the appended claims shouldgenerally be construed to mean “one or more” unless specified otherwiseor clear from the context to be directed to a singular form.

The techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband-CDMA (W-CDMA) and other variants of CDMA. Further, cdma2000covers IS-2000, IS-95 and IS-856 standards. A TDMA system may implementa radio technology such as Global System for Mobile Communications(GSM). An OFDMA system may implement a radio technology such as EvolvedUTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA and E-UTRA are partof Universal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) is a release of UMTS that uses E-UTRA, which employsOFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTEand GSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). Additionally, cdma2000 and UMBare described in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). Further, such wireless communicationsystems may additionally include peer-to-peer (e.g., mobile-to-mobile)ad hoc network systems often using unpaired unlicensed spectrums, 802.xxwireless LAN, BLUETOOTH and any other short- or long-range, wirelesscommunication techniques.

Various aspects or features will be presented in terms of systems thatmay include a number of devices, components, modules, and the like. Itis to be understood and appreciated that the various systems may includeadditional devices, components, modules, etc. and/or may not include allof the devices, components, modules etc. discussed in connection withthe figures. A combination of these approaches may also be used.

Referring to FIG. 1, an example wireless communication system 100 withpossible access point interference is illustrated. System 100 comprisesa device 102 that can communicate with a serving access point 104 toreceive access to a wireless network and/or one or more componentsthereof. System 100 can also comprise another access point 106 withwhich device 102 can potentially interfere. Device 102 can be a UE, amodem (or other tethered device), a portion thereof, and/or the like.Access points 104 and/or 106 can each be a macrocell access point,femtocell access point (such as a Home Node B or Home evolved Node B,collectively referred to herein as H(e)NB), picocell access point,microcell access point, a mobile base station, a relay node, a device(e.g., communicating in peer-to-peer or ad-hoc mode), a portion thereof,and/or the like.

According to an example, serving access point 104 can transmit signalsto device 102 to communicate therewith, and device 102 can potentiallyinterfere with access point 106 while transmitting signals 110 toserving access point 104 (e.g., where device 102 is within a thresholdgeographic range of access point 106). Described herein are variousenhancements to mitigate such interference 112. In one example, servingaccess point 104 can be a macrocell access point, or another accesspoint with planned deployment, and access point 106 can be a femtocell,picocell, microcell, etc. access point with unplanned deployment.Interference 112 from device 102 to access point 106 can result at leastin part to the unplanned deployment of access point 106.

In one example, as device 102 moves within a threshold distance ofaccess point 106 and/or causes a threshold level of interferencethereto, serving access point 104 can lower a IFHO handover thresholdrelated to the device 102 to facilitate IFHO of the device 102. In thisexample, device 102 can notify serving access point 104 of one or moreparameters regarding access point 106, from which serving access point104 can discern whether to modify the IFHO threshold for the device.When the device 102 is handed over to another frequency, for example,device 102 can likely cease from interfering with communications ofaccess point 106, as device 102 will accordingly communicate over adifferent frequency.

In another example, access point 106 can detect interference over athreshold level from device 102, and can switch to a hybrid or openaccess mode (e.g., from a closed access mode) to allow devicesinterfering with access point 106, such as device 102, to handover toaccess point 106. In this example, access point 106 can detectinterference based at least in part on a measured noise level, decodingcommunications from device 102 (e.g., and determining device 102 is nota served device), etc. In yet another example, serving access point 104can notify access point 106 of possible interference from device 102(e.g., by initiating a backhaul link 114 to access point 106 based onreceiving one or more parameters regarding access point 106 from device102). Thus, upon switching to hybrid or open access mode, device 102 canbe handed over from serving access point 104 to access point 106.

Moreover, in an example, upon determining that device 102 may cause athreshold level of interference to access point 106, serving accesspoint 104 can limit a data rate for device 102 communications withserving access point 104. For example, serving access point 104 canlower a number of resources assigned to device 102. In any case, servingaccess point 104 can lower the data rate based additionally oralternatively in part on observing strength and/or quality of pilotsignals from serving access point 104 at device 102. Also, in anexample, access point 106 can detect interference from one or moredevices, which can be based on detecting a rise-over-thermal (RoT) overa threshold level, an uplink received signal strength indication (RSSI)over a threshold level, an indication of possible interference receivedfrom serving access point 104, etc., and can accordingly boosttransmission power of access point 106 to possibly cause IFHO of thedevice (e.g., device 102). In this example, device 102 reports theinterference or noise level to serving access point 104, and servingaccess point can trigger the IFHO to an access point in anotherfrequency based on the interference or noise level exceeding the IFHOthreshold.

In another example, serving access point 104 can be a femtocell accesspoint, and device 102 communicating with serving access point 104 cancause interference to a macrocell access point 106. In this example,serving access point 104 can determine a pathloss edge target not onlybased on a downlink coverage requirement and downlink transmission powerlimitation, but also on the uplink performance and interference ofdevice 102 and/or other devices served by serving access point 104.Thus, for example, where serving access point 104 is notified of orotherwise determines interference caused to access point 106, servingaccess point 104 can decrease a pathloss edge target, which can modify acoverage area of serving access point 104 and cause device 102 tohandover to access point 106 or one or more other access points.

Turning to FIG. 2, an example wireless communication system 200 isillustrated for mitigating interference caused by devices communicatingwith an access point. System 200 comprises a device 202 thatcommunicates with a serving access point 204 to receive wireless networkaccess, as described. In addition, system 200 can include another accesspoint 206 with which device 202 can potentially interfere due at leastin part to communicating with serving access point 204. For example,deployment of serving access point 204 can result in interference toother access points in the vicinity of serving access point 204 (notshown), whether caused by serving access point 204, device 202 or otherdevices communicating with serving access point 204, etc. As described,for example, device 202 can be a UE, modem, etc., and serving accesspoint 204 and access point 206 can each be a macrocell, femtocell,picocell, or similar access point, an H(e)NB, a mobile base station, adevice (e.g., communicating in peer-to-peer or ad-hoc mode), a portionthereof, and/or the like.

Device 202 can optionally comprise an access point measuring component208 for receiving and analyzing signals from one or more access points,and/or a measurement reporting component 210 for communicatingmeasurements of the signals to one or more access points. Serving accesspoint 204 can comprise an interference determining component 212 fordiscerning a level of potential interference caused by one or moredevices, and an optional IFHO threshold modifying component 214 foradjusting an IFHO threshold for the one or more devices based on thelevel of potential interference. Serving access point 204 alsooptionally comprises a data rate determining component 216 for adjustinga data rate for the one or more devices based on the level of potentialinterference, and/or a scheduling component 218 for modifying a resourceallocation based on the adjusted data rate.

According to an example, device 202 can communicate with serving accesspoint 204 to receive access in a wireless network, and interferencedetermining component 212 can determine potential interference of device202 to one or more access points. For example, the potentialinterference can be determine with respect to a specific access point,such as access point 206, or more generally based on parameters relatedto device 202. In one example, access point measuring component 208 canperiodically measure signals from other access points, such as accesspoint 206, and measurement reporting component 210 can report themeasurements to serving access point 204.

For example, this can be part of a handover procedure where measurementreporting component 210 formulates the measurement report of indicatedsignal measurements (e.g., signal-to-noise ratio (SNR), received signalpower, Ecp, over total power, Io, or other signal strength or qualitymeasurements, etc.) to other access points such that serving accesspoint 204 can evaluate the measurement report to determine whether tohandover device 202 to one or more of the other access points (e.g.,where the one or more of the other access points have signalmeasurements that are improved over measurements of serving access point204 at device 202). This can be part of handover or reselection in oneor more wireless communication technologies. In another example, accesspoint measuring component 208 can measure one or more access pointsaccording to a timer or other event, based on a request from servingaccess point 204, and/or the like.

In an example, interference determining component 212 can determine thatdevice 202 may potentially cause interference to one or more accesspoints, such as access point 206. For example, this can includereceiving a measurement report from device 202 and determining ameasurement of a signal from access point 206 (e.g., SNR)) is over athreshold level, where the threshold level can be set to indicateinterference and/or that a corresponding device is almost interfering.Thus, in this example, device 202 is within a distance of access point206, based on signal measurement, such that device 202 may causeinterference, or about to begin causing interference, thereto. Inanother example, interference determining component 212 can determineinterference of device 202 based on receiving an indication ofinterference from access point 206 (e.g., over a backhaul link).

Moreover, in an example, interference determining component 212 candetect potential interference of device 202 to one or more access pointsin general based at least in part on a reported measurement of a signalfrom serving access point 204. For example, this can be reported bydevice 202 as channel quality indicator (CQI) or similar controlinformation over a control channel. Thus, in this example, interferencecan be determined without measurement reports. Where the reportedmeasurement of the signal (e.g., SNR) is below a threshold level, thiscan indicate device 202 is near another access point, which can bejamming the pilot signal from serving access point 204.

In any case, once potential interference is determined serving accesspoint 204 can attempt to mitigate such interference to access point 206in one or more aspects. In one example, IFHO threshold modifyingcomponent 214 can adjust an IFHO threshold for device 202 based on thepotential interference to cause device 202 to perform an inter-frequencyhandover. As described, serving access point 204 can institute IFHOthresholds for devices to facilitate performing IFHO of the device wherea measurement of serving access point 204 reported by the device 202(e.g., SNR) is less than a threshold level (e.g., −16 decibel (dB) for amacrocell access point). The device can accordingly report the signalmeasurement with the measurement report, periodically based on one ormore timers, based on one or more events, and/or the like.

Thus, where interference determining component 212 determines potentialinterference of device 202 to access point 206 (e.g., based ondetermining that a SNR or similar metric of access point 206 received ina measurement report, etc. is over a threshold level), IFHO thresholdmodifying component 214 can decrease the IFHO threshold for device 202.Where device 202 is nearing access point 206, the device's reportedsignal measurement to serving access point 204 can decrease asadditional noise is received from access point 206. Thus, the IFHOthreshold decrease can cause device 202 to perform IFHO sooner. Once theIFHO is performed, device 202 can no longer interfere with access point206 as it is on another frequency (and/or interference can be lessenedin the case where device 202 is handed over to an adjacent frequency).It is to be appreciated that IFHO threshold modifying component 214 canadjust the IFHO threshold in fixed value, according to the potentialinterference (e.g., determine an adjustment value based at least in parton the reported signal measurement of access point 206), etc.

In another example, upon determining potential interference of device202 to one or more access points, such as access point 206, servingaccess point 204 can limit a data rate for device 202 to mitigateoccurrence of interference. In this example, based on determining theinterference, data rate determining component 216 can decrease a datarate for device 202, such as a maximum allowed data rate. In oneexample, this can include scheduling component 218 modifying a resourceallocation to device 202 based on the data rate limitation. Similarly,as with the IFHO threshold, the data rate can be adjusted in fixedvalue, as a function of the potential interference determined, and/orthe like. In addition, data rate determining component 216 can increasea data rate when the threat of interference has ceased (e.g., when areported signal measurement of access point 206 or other access pointshas decreased below a threshold level, etc.).

Referring to FIG. 3, an example wireless communication system 300 isillustrated for mitigating interference from one or more devicescommunicating with another access point. System 300 comprises a device302 that communicates with a serving access point 304 to receive accessto a wireless network. System 300 also comprises an access point 306,with which device 302 can potentially interfere (which can includeinterfering with devices communicating with access point 306) whiletransmitting signals to access point 304. In this regard, for example,serving access point 304 and/or access point 306 can be deployed withina vicinity of one another. As described, device 302 can be a UE, modem,etc., and serving access point 304 and/or access point 206 can each be amacrocell, femtocell, or picocell access point, etc.

Access point 306 comprises an interference detecting component 308 fordetermining that one or more devices potentially interfere withcommunications from access point 306, an optional access mode component310 for modifying an access point of access point 306 based on thepotential interference, and/or an optional downlink transmit powercomponent 312 for adjusting a downlink transmit power of access point306 based on the potential interference.

According to an example, device 302 can communicate with serving accesspoint 304 to receive wireless network access and can interfere withaccess point 306 when communicating with serving access point 304. Forexample, device 302 can be near access point 306, which can be afemtocell access point, while communicating with serving access point304, which can be a macrocell access point. Access point 306, however,can advertise and operate in a closed access mode offering access tomember devices of a closed subscriber group (CSG) or other restrictedassociation to which device 302 is not a member. For example,interference detecting component 308 can determine interference fromdevice 302, which is a non-member device, based at least in part onreceiving signals therefrom intended for serving access point 304,receiving a notification of interference or potential interference fromserving access point 304 (e.g., based on serving access point 304determining potential interference as described with reference to FIG.2) over a backhaul link thereto, and/or the like. In another example,interference detecting component 308 can determine the interferenceand/or a level thereof based on a total wideband power measurement, aRoT measurement, an out-of-cell interference measurement (e.g.,measuring total power level, Ioc, over a noise level, No), and/or thelike.

In one example, upon detecting interference from device 302 and/ordetecting interference over a threshold level, access mode component 310can determine to advertise a hybrid or open access mode to allowinterfering non-member device 302 to communicate with access point 306.In this example, device 302 can detect signals from access point 306that advertise the hybrid or open access mode (e.g., in systeminformation blocks transmitted by the access point 306) and can includeaccess point 306 in a measurement report for handover based ondetermining access point 306 is in hybrid or open access mode. Servingaccess point 304 can then receive the measurement report and handoverdevice 302 to access point 306 upon determining radio conditionsreported for access point 306 are improved over those of serving accesspoint 304. Thus, device 302 can communicate with access point 306instead of interfering therewith. In addition, once device 302 is handedover to another access point from access point 306, or communicationswith device 302 at access point 306 have otherwise ended, access modecomponent 310 can switch back to closed access mode, in one example.

In another example, downlink transmit power component 312 can modify adownlink transmit power of access point 306 based on the interferenceand/or a level of interference detected. By increasing or boostingdownlink transmission power of access point 306, for example, device 302can report a lower signal to interference ratio to serving access point304 since the interference caused by access point 306 to device 302 hasbeen increased. Thus, as described above, this can cause serving accesspoint 304 to initiate IFHO of the device 302 where the ratio is below athreshold level, in which case device 302 can no longer interfere withaccess point 306.

For example, downlink transmit power component 312 can boost downlinktransmit power according to a power boosting pattern. The power boostscan be grouped into one or more clusters of N bursts, where N is apositive integer, and each burst can have an associated time duration.For each burst, downlink transmit power component 312 can increment thedownlink transmit power. For example, once downlink transmit powercomponent 312 reaches N bursts, downlink transmit power component 312can cease boosting downlink transmit power for another time duration toprevent causing interference to one or more neighboring access points.Moreover, for example, downlink transmit power component 312 can boostdownlink transmit power of a control channel for device 302, a datachannel, and/or the like. In addition, the time durations and powerboost values can be selected so as to mitigate bursty interferencecaused to other devices communicating with other access points. Onceinterference is no longer detected from the device 302 (e.g., device 302performed IFHO and now operates on a different frequency), downlinktransmit power component 312 can return to an original downlink transmitpower.

FIG. 4 illustrates an example downlink transmit power boost patterngraph 400 showing total downlink transmit power over time. As described,the downlink transmit power can be boosted for an access point upondetecting interference in an attempt to cause IFHO to be performed foran interfering device based on the device determining a higher noiselevel based on the boosted downlink transmit power. An original powerlevel for the access point can be at 402. Upon detecting interferencefrom one or more devices, as described above, the downlink transmitpower can be boosted for time duration 404 to level 406. As described,boosting the downlink transmit power in this regard can cause aninterfering device to report additional noise to a serving base station,which can cause IFHO for the device. The access point can lower thedownlink transmit power to original level 402 for a time duration 408.If however, the device is still interfering after a time duration 408,access point can boost the downlink transmit power by a difference of410 to level 412 in an attempt cause IFHO for the interfering device,and so on until a last burst 414 in the cluster of bursts. Subsequently,the device can return to original power level 402 for an extended timeduration 416 to prevent causing downlink interference to neighboringcell devices. Then, if interference is still present after time duration416, another cluster of downlink transmit power boosts (or portionthereof) can occur until interference subsides, as described above.

Referring to FIG. 5, an example wireless communication system 500 isillustrated for preventing devices from interfering with one or moreaccess points. System 500 comprises a device 502 that communicates witha serving access point 504 to receive access to a wireless network. Asdescribed, for example, device 502 can potentially interfere with accesspoint 506 while transmitting signals to serving access point 504 (whichcan include interfering with devices communicating with access point506) and/or vice versa. In this regard, for example, access points 504and/or 506 can be deployed within a vicinity of one another. Asdescribed, device 502 can be a UE, modem, etc., access points 504 and/or506 can each be a macrocell, femtocell, or picocell access point, etc.

Serving access point 504 can comprise an interference determiningcomponent 508 for determining that one or more devices may cause or arecausing interference to one or more other access points, and a pathlossedge target adjusting component 510 for modifying a pathloss edge targetof serving access point 504 to mitigate the interference. A pathlossedge target can relate to a desired pathloss experienced at the edge ofcoverage of serving access point 504. Thus, adjusting the pathloss edgetarget can effectively adjust a coverage of the serving access point504. For example, a transmission power for the serving access point 504can be computed from the pathloss edge target to achieve the targetpathloss at the edge as reported by one or more devices communicatingwith the serving access point 504.

According to an example, device 502 can cause interference to accesspoint 506 when transmitting signals to serving access point 504, asdescribed. For example, interference determining component 508 candetermine the interference, as described above, based on measurements ofaccess point 506 received from device 502 (e.g., in a measurement reportfor handover), a determined SNR at device 502 of pilot transmission byserving access point 504, and/or the like. In addition, as described,access point 506 can notify serving access point 504 of interferencefrom device 502 over a backhaul link.

Upon interference determining component 508 determining interferencecaused by one or more devices, such as device 502, to one or more accesspoints, such as access point 506, pathloss edge target adjustingcomponent 510 can modify a pathloss edge target to reduce a coveragearea of the serving access point 504. In one example, pathloss edgetarget adjusting component 510 can modify the pathloss edge target uponinitialization of serving access point 504 based further in part on adownlink coverage requirement and downlink transmit power limitation.For example, the pathloss edge target can be reduced as a function of alevel of the determined interference, as described, shrinking thecoverage area of serving access point 504. This may cause device 502,which would otherwise communicate with serving access point 504, tocommunicate with another access point, which may accordingly mitigateinterference to access point 506.

Referring to FIGS. 6-9, example methodologies relating to mitigatinginterference in wireless communications are illustrated. While, forpurposes of simplicity of explanation, the methodologies are shown anddescribed as a series of acts, it is to be understood and appreciatedthat the methodologies are not limited by the order of acts, as someacts may, in accordance with one or more embodiments, occur in differentorders and/or concurrently with other acts from that shown and describedherein. For example, it is to be appreciated that a methodology couldalternatively be represented as a series of interrelated states orevents, such as in a state diagram. Moreover, not all illustrated actsmay be required to implement a methodology in accordance with one ormore embodiments.

Referring to FIG. 6, an example methodology 600 is illustrated formitigating interference in a wireless network. At 602, it can bedetermined that a served device potentially interferes one or moreaccess points. As described, this can be determined based at least inpart on measurements of the one or more access points from the serveddevice, a pilot SNR measurement reported by the device, a receivedindication of interference from the one or more access points over abackhaul connection, and/or the like. At 604, an IFHO threshold or datarate can be adjusted for the served device based at least in part on thedetermining Thus, for example, decreasing the IFHO threshold can likelycause the device to perform IFHO to mitigate further interference fromthe device. Modifying the data rate can mitigate the occurrence ofinterference from the device by lowering a resource allocation thereto.

Turning to FIG. 7, an example methodology 700 is displayed that switchesan access mode to mitigate interference. At 702, a closed access modecan be operated allowing communications with member devices. Forexample, the closed access mode can provide restricted access to devicesin a CSG. At 704, interference can be detected from one or morenon-member devices served by one or more access points. For example, theinterference can be detected by receiving signals from the one or morenon-member devices intended for the one or more access points. Inanother example, the one or more access points can inform of theinterference. At 706, a hybrid or open access mode can be switched toallow communications with the one or more non-member devices based onthe detected interference. Thus, the interference can be mitigated byallowing the devices to be handed over from the one or more accesspoints.

Referring to FIG. 8, an example methodology 800 for boosting a transmitpower to mitigate interference from one or more devices is illustrated.At 802, interference from one or more devices communicating with one ormore access points can be detected. For example, the interference can bedetected based at least in part on measurements received from the one ormore devices, a reported pilot SNR from the one or more devices,received as an indication of interference over a backhaul connectionwith the one or more access points, and/or the like. At 804, a downlinktransmit power can be increased according to a boosting pattern overtime based on detecting the interference. As described, the boostingpattern can be a predefined or hardcoded, configured, etc. pattern thatescalates boosting power over one or more boost clusters untilinterference is no longer detected from the one or more devices.

Turning to FIG. 9, an example methodology 900 is depicted for modifyinga coverage area based on determining potential interference. At 902, itcan be determined that a served device potentially interferes one ormore access points. For example, as described, this can be determinedbased at least in part on measurements of the one or more access pointsfrom the served device, an indication of interference received from theone or more access points, and/or the like. At 904, a pathloss edgetarget can be adjusted based at least in part on the determining Thus, acoverage area can become smaller based on adjusting the pathloss edgetarget. For example, this can be performed at initialization, and thuspotential interference is mitigated based on the smaller coverage area,since potentially interfering devices can connect to the one or moreaccess points instead.

It will be appreciated that, in accordance with one or more aspectsdescribed herein, inferences can be made regarding determining ordetecting interference, determining a IFHO threshold adjustment, whetherto switch an access mode, a downlink transmit power boost, a pathlossedge target, etc., and/or the like, as described. As used herein, theterm to “infer” or “inference” refers generally to the process ofreasoning about or inferring states of the system, environment, and/oruser from a set of observations as captured via events and/or data.Inference can be employed to identify a specific context or action, orcan generate a probability distribution over states, for example. Theinference can be probabilistic—that is, the computation of a probabilitydistribution over states of interest based on a consideration of dataand events. Inference can also refer to techniques employed forcomposing higher-level events from a set of events and/or data. Suchinference results in the construction of new events or actions from aset of observed events and/or stored event data, whether or not theevents are correlated in close temporal proximity, and whether theevents and data come from one or several event and data sources.

FIG. 10 is an illustration of a system 1000 that facilitatescommunicating with one or more devices using wireless communications.System 1000 comprises a base station 1002, which can be substantiallyany base station (e.g., a small base station, such as a femtocell,picocell, etc., mobile base station . . . ), a relay, etc., having areceiver 1010 that receives signal(s) from one or more mobile devices1004 through a plurality of receive antennas 1006 (e.g., which can be ofmultiple network technologies, as described), and a transmitter 1036that transmits to the one or more mobile devices 1004 through aplurality of transmit antennas 1008 (e.g., which can be of multiplenetwork technologies, as described). In addition, in one example,transmitter 1036 can transmit to the mobile devices 1004 over a wiredfront link. Receiver 1010 can receive information from one or morereceive antennas 1006 and is operatively associated with a demodulator1012 that demodulates received information. In addition, in an example,receiver 1010 can receive from a wired backhaul link. Demodulatedsymbols are analyzed by a processor 1014. For example, processor 1014can be a processor dedicated to analyzing information received byreceiver 1010 and/or generating information for transmission by atransmitter 1008, a processor that controls one or more components ofbase station 1002, and/or a processor that both analyzes informationreceived by receiver 1010, generates information for transmission bytransmitter 1008, and controls one or more components of base station1002, etc.

In addition, processor 1010 can be coupled to a memory 1016 that storesinformation related to estimating a signal (e.g., pilot) strength and/orinterference strength, data to be transmitted to or received from mobiledevice(s) 1004 (or a disparate base station (not shown)), and/or anyother suitable information related to performing the various actions andfunctions set forth herein, such as a determined interference, an IFHOthreshold, a data rate, etc.

It will be appreciated that memory 1016, or other data stores describedherein, can be either volatile memory or nonvolatile memory, or caninclude both volatile and nonvolatile memory. By way of illustration,and not limitation, nonvolatile memory can include read only memory(ROM), programmable ROM (PROM), electrically programmable ROM (EPROM),electrically erasable PROM (EEPROM), or flash memory. Volatile memorycan include random access memory (RAM), which acts as external cachememory. By way of illustration and not limitation, RAM is available inmany forms such as synchronous RAM (SRAM), dynamic RAM (DRAM),synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhancedSDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).The memory 1016 of the subject systems and methods is intended tocomprise, without being limited to, these and any other suitable typesof memory.

Processor 1014 is further optionally coupled to an interferencedetermining component 1018, which can be similar to interferencedetermining components 212 and/or 508, an IFHO threshold modifyingcomponent 1020, which can be similar to IFHO threshold modifyingcomponent 214, a data rate determining component 1022, which can besimilar to data rate determining component 216, and/or a schedulingcomponent 1024, which can be similar to scheduling component 218.Processor 1014 can further be optionally coupled to an interferencedetecting component 1026, which can be similar to interference detectingcomponent 308, an access mode component 1028, which can be similar toaccess mode component 310, a downlink transmit power component 1030,which can be similar to downlink transmit power component 312, and/or apathloss edge target adjusting component 1032, which can be similar topathloss edge target adjusting component 510.

Moreover, for example, processor 1014 can modulate signals to betransmitted using modulator 1034, and transmit modulated signals usingtransmitter 1036. Transmitter 1036 can transmit signals to mobiledevices 1004 over Tx antennas 1008. Furthermore, although depicted asbeing separate from the processor 1014, it is to be appreciated that theinterference determining component 1018, IFHO threshold modifyingcomponent 1020, data rate determining component 1022, schedulingcomponent 1024, interference detecting component 1026, access modecomponent 1028, downlink transmit power component 1030, pathloss edgetarget adjusting component 1032, demodulator 1012, and/or modulator 1034can be part of the processor 1014 or multiple processors (not shown),and/or stored as instructions in memory 1016 for execution by processor1014.

With reference to FIG. 11, illustrated is a system 1100 that mitigatesinterference caused by one or more served devices. For example, system1100 can reside at least partially within an access point, etc. It is tobe appreciated that system 1100 is represented as including functionalblocks, which can be functional blocks that represent functionsimplemented by a processor, software, or combination thereof (e.g.,firmware). System 1100 includes a logical grouping 1102 of electricalcomponents that can act in conjunction. For instance, logical grouping1102 can include an electrical component for determining that a serveddevice potentially interferes one or more access points 1104. Asdescribed, for example, this can be determined based on receivedmeasurements of the one or more access points from the served device, adetermined pilot SNR reported by the served device, an indication fromthe one or more access points, etc.

Further, logical grouping 1102 can comprise an electrical component foradjusting an IFHO threshold or a data rate for the served device basedat least in part on the determining 1106. Thus, as described forexample, based on the determined interference of the served device, theIFHO threshold can be lowered to facilitate handing over the serveddevice in another frequency once the served device experiences the lowerthreshold level of interference from the one or more access points,and/or a data rate for the served device can be lowered to facilitatelessening transmission opportunities for the served device. For example,electrical component 1104 can include an interference determiningcomponent 212, as described above. In addition, for example, electricalcomponent 1106, in an aspect, can include an IFHO threshold modifyingcomponent 214 and/or a data rate determining component 216, as describedabove.

Additionally, system 1100 can include a memory 1108 that retainsinstructions for executing functions associated with the electricalcomponents 1104 and 1106. While shown as being external to memory 1108,it is to be understood that one or more of the electrical components1104 and 1106 can exist within memory 1108. In one example, electricalcomponents 1104 and 1106 can comprise at least one processor, or eachelectrical component 1104 and 1106 can be a corresponding module of atleast one processor. Moreover, in an additional or alternative example,electrical components 1104 and 1106 can be a computer program productcomprising a computer readable medium, where each electrical component1104 and 1106 can be corresponding code.

With reference to FIG. 12, illustrated is a system 1200 that switchesaccess modes based on detecting interference from one or more devices.For example, system 1200 can reside at least partially within an accesspoint, etc. It is to be appreciated that system 1200 is represented asincluding functional blocks, which can be functional blocks thatrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware). System 1200 includes a logical grouping 1202of electrical components that can act in conjunction. For instance,logical grouping 1202 can include an electrical component for operatingin a closed access mode allowing communications with member devices andswitching to a hybrid or open access mode based on detected interference1204. As described, for example, this can allow interfering devices toconnect to system 1200 mitigating interference thereto.

Further, logical grouping 1202 can comprise an electrical component fordetecting interference from one or more non-member devices served by oneor more access points 1206. As described for example, detectinginterference can be based at least in part on observing signals receivedfrom the one or more non-member devices intended for the one or moreaccess points, receiving an indication of potential interference fromthe one or more access points, and/or the like. For example, electricalcomponent 1204 can include an interference detecting component 308, asdescribed above. In addition, for example, electrical component 1206, inan aspect, can include an access mode component 310, as described above.

Additionally, system 1200 can include a memory 1208 that retainsinstructions for executing functions associated with the electricalcomponents 1204 and 1206. While shown as being external to memory 1208,it is to be understood that one or more of the electrical components1204 and 1206 can exist within memory 1208. In one example, electricalcomponents 1204 and 1206 can comprise at least one processor, or eachelectrical component 1204 and 1206 can be a corresponding module of atleast one processor. Moreover, in an additional or alternative example,electrical components 1204 and 1206 can be a computer program productcomprising a computer readable medium, where each electrical component1204 and 1206 can be corresponding code.

With reference to FIG. 13, illustrated is a system 1300 for attemptingto cause IFHO handover for an interfering device. For example, system1300 can reside at least partially within an access point, etc. It is tobe appreciated that system 1300 is represented as including functionalblocks, which can be functional blocks that represent functionsimplemented by a processor, software, or combination thereof (e.g.,firmware). System 1300 includes a logical grouping 1302 of electricalcomponents that can act in conjunction. For instance, logical grouping1302 can include an electrical component for detecting interference fromone or more devices communicating with one or more access points 1304.As described for example, detecting interference can be based at leastin part on observing signals received from the one or more non-memberdevices intended for the one or more access points, receiving anindication of potential interference from the one or more access points,and/or the like.

Further, logical grouping 1302 can comprise an electrical component forincreasing a downlink transmit power according to a boosting patternover time based on detecting the interference 1306. Thus, as describedfor example, the downlink transmit power is boosted by one or morevalues over time intervals in one or more clusters until theinterference is no longer present (e.g., until IFHO is performed for thedevice based on interference caused thereto by the downlink transmitpower boosting). For example, electrical component 1304 can include aninterference detecting component 308, as described above. In addition,for example, electrical component 1306, in an aspect, can include adownlink transmit power component 312, as described above.

Additionally, system 1300 can include a memory 1308 that retainsinstructions for executing functions associated with the electricalcomponents 1304 and 1306. While shown as being external to memory 1308,it is to be understood that one or more of the electrical components1304 and 1306 can exist within memory 1308. In one example, electricalcomponents 1304 and 1306 can comprise at least one processor, or eachelectrical component 1304 and 1306 can be a corresponding module of atleast one processor. Moreover, in an additional or alternative example,electrical components 1304 and 1306 can be a computer program productcomprising a computer readable medium, where each electrical component1304 and 1306 can be corresponding code.

With reference to FIG. 14, illustrated is a system 1400 for determininga coverage area for an access point based on determined potentialinterference. For example, system 1400 can reside at least partiallywithin an access point, etc. It is to be appreciated that system 1400 isrepresented as including functional blocks, which can be functionalblocks that represent functions implemented by a processor, software, orcombination thereof (e.g., firmware). System 1400 includes a logicalgrouping 1402 of electrical components that can act in conjunction. Forinstance, logical grouping 1402 can include an electrical component fordetermining that a served device potentially interferes with one or moreaccess points 1404. As described, for example, this can be determinedbased on received measurements of the one or more access points from theserved device, a determined pilot SNR reported by the served device, anindication from the one or more access points, etc.

Further, logical grouping 1402 can comprise an electrical component foradjusting a pathloss edge target based at least in part on thedetermining 1406. Thus, as described, the effective coverage area ismodified based on the pathloss edge target, and potential interferencecan be mitigated since devices that would otherwise connect can connectwith the one or more access points, and thus not cause interferencethereto. For example, electrical component 1404 can include aninterference determining component 508, as described above. In addition,for example, electrical component 1406, in an aspect, can include apathloss edge target adjusting component 510, as described above.

Additionally, system 1400 can include a memory 1408 that retainsinstructions for executing functions associated with the electricalcomponents 1404 and 1406. While shown as being external to memory 1408,it is to be understood that one or more of the electrical components1404 and 1406 can exist within memory 1408. In one example, electricalcomponents 1404 and 1406 can comprise at least one processor, or eachelectrical component 1404 and 1406 can be a corresponding module of atleast one processor. Moreover, in an additional or alternative example,electrical components 1404 and 1406 can be a computer program productcomprising a computer readable medium, where each electrical component1404 and 1406 can be corresponding code.

Referring now to FIG. 15, a wireless communication system 1500 isillustrated in accordance with various embodiments presented herein.System 1500 comprises a base station 1502 that can include multipleantenna groups. For example, one antenna group can include antennas 1504and 1506, another group can comprise antennas 1508 and 1510, and anadditional group can include antennas 1512 and 1514. Two antennas areillustrated for each antenna group; however, more or fewer antennas canbe utilized for each group. Base station 1502 can additionally include atransmitter chain and a receiver chain, each of which can in turncomprise a plurality of components associated with signal transmissionand reception (e.g., processors, modulators, multiplexers, demodulators,demultiplexers, antennas, etc.), as is appreciated.

Base station 1502 can communicate with one or more mobile devices suchas mobile device 1516 and mobile device 1522; however, it is to beappreciated that base station 1502 can communicate with substantiallyany number of mobile devices similar to mobile devices 1516 and 1522.Mobile devices 1516 and 1522 can be, for example, cellular phones, smartphones, laptops, handheld communication devices, handheld computingdevices, satellite radios, global positioning systems, PDAs, and/or anyother suitable device for communicating over wireless communicationsystem 1500. As depicted, mobile device 1516 is in communication withantennas 1512 and 1514, where antennas 1512 and 1514 transmitinformation to mobile device 1516 over a forward link 1518 and receiveinformation from mobile device 1516 over a reverse link 1520. Moreover,mobile device 1522 is in communication with antennas 1504 and 1506,where antennas 1504 and 1506 transmit information to mobile device 1522over a forward link 1524 and receive information from mobile device 1522over a reverse link 1526. In a frequency division duplex (FDD) system,forward link 1518 can utilize a different frequency band than that usedby reverse link 1520, and forward link 1524 can employ a differentfrequency band than that employed by reverse link 1526, for example.Further, in a time division duplex (TDD) system, forward link 1518 andreverse link 1520 can utilize a common frequency band and forward link1524 and reverse link 1526 can utilize a common frequency band.

Each group of antennas and/or the area in which they are designated tocommunicate can be referred to as a sector of base station 1502. Forexample, antenna groups can be designed to communicate to mobile devicesin a sector of the areas covered by base station 1502. In communicationover forward links 1518 and 1524, the transmitting antennas of basestation 1502 can utilize beamforming to improve signal-to-noise ratio offorward links 1518 and 1524 for mobile devices 1516 and 1522. Also,while base station 1502 utilizes beamforming to transmit to mobiledevices 1516 and 1522 scattered randomly through an associated coverage,mobile devices in neighboring cells can be subject to less interferenceas compared to a base station transmitting through a single antenna toall its mobile devices. Moreover, mobile devices 1516 and 1522 cancommunicate directly with one another using a peer-to-peer or ad hoctechnology as depicted. According to an example, system 1500 can be amultiple-input multiple-output (MIMO) communication system. In addition,for example, base station 1502 can set a IFHO threshold, data rate,etc., for a mobile device 1516 and/or 1522 based on determiningpotential interference to other access points, switch among access modesbased on potential interference, boost a downlink transmit power basedon potential interference, adjust a pathloss edge target, and/or thelike, as described.

FIG. 16 shows an example wireless communication system 1600. Thewireless communication system 1600 depicts one base station 1610 and onemobile device 1650 for sake of brevity. However, it is to be appreciatedthat system 1600 can include more than one base station and/or more thanone mobile device, wherein additional base stations and/or mobiledevices can be substantially similar or different from example basestation 1610 and mobile device 1650 described below. In addition, it isto be appreciated that base station 1610 and/or mobile device 1650 canemploy the systems (FIGS. 1-3, 5, and 10-15), boosting patterns (FIG.4), and/or methods (FIGS. 6-9) described herein to facilitate wirelesscommunication there between. For example, components or functions of thesystems and/or methods described herein can be part of a memory 1632and/or 1672 or processors 1630 and/or 1670 described below, and/or canbe executed by processors 1630 and/or 1670 to perform the disclosedfunctions.

At base station 1610, traffic data for a number of data streams isprovided from a data source 1612 to a transmit (TX) data processor 1614.According to an example, each data stream can be transmitted over arespective antenna. TX data processor 1614 formats, codes, andinterleaves the traffic data stream based on a particular coding schemeselected for that data stream to provide coded data.

The coded data for each data stream can be multiplexed with pilot datausing orthogonal frequency division multiplexing (OFDM) techniques.Additionally or alternatively, the pilot symbols can be frequencydivision multiplexed (FDM), time division multiplexed (TDM), or codedivision multiplexed (CDM). The pilot data is typically a known datapattern that is processed in a known manner and can be used at mobiledevice 1650 to estimate channel response. The multiplexed pilot andcoded data for each data stream can be modulated (e.g., symbol mapped)based on a particular modulation scheme (e.g., binary phase-shift keying(BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying(M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) selected forthat data stream to provide modulation symbols. The data rate, coding,and modulation for each data stream can be determined by instructionsperformed or provided by processor 1630.

The modulation symbols for the data streams can be provided to a TX MIMOprocessor 1620, which can further process the modulation symbols (e.g.,for OFDM). TX MIMO processor 1620 then provides N_(T) modulation symbolstreams to N_(T) transmitters (TMTR) 1622 a through 1622 t. In variousembodiments, TX MIMO processor 1620 applies beamforming weights to thesymbols of the data streams and to the antenna from which the symbol isbeing transmitted.

Each transmitter 1622 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel.Further, N_(T) modulated signals from transmitters 1622 a through 1622 tare transmitted from N_(T) antennas 1624 a through 1624 t, respectively.

At mobile device 1650, the transmitted modulated signals are received byN_(R) antennas 1652 a through 1652 r and the received signal from eachantenna 1652 is provided to a respective receiver (RCVR) 1654 a through1654 r. Each receiver 1654 conditions (e.g., filters, amplifies, anddownconverts) a respective signal, digitizes the conditioned signal toprovide samples, and further processes the samples to provide acorresponding “received” symbol stream.

An RX data processor 1660 can receive and process the N_(R) receivedsymbol streams from N_(R) receivers 1654 based on a particular receiverprocessing technique to provide N_(T) “detected” symbol streams. RX dataprocessor 1660 can demodulate, deinterleave, and decode each detectedsymbol stream to recover the traffic data for the data stream. Theprocessing by RX data processor 1660 is complementary to that performedby TX MIMO processor 1620 and TX data processor 1614 at base station1610.

The reverse link message can comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message can be processed by a TX data processor 1638, whichalso receives traffic data for a number of data streams from a datasource 1636, modulated by a modulator 1680, conditioned by transmitters1654 a through 1654 r, and transmitted back to base station 1610.

At base station 1610, the modulated signals from mobile device 1650 arereceived by antennas 1624, conditioned by receivers 1622, demodulated bya demodulator 1640, and processed by a RX data processor 1642 to extractthe reverse link message transmitted by mobile device 1650. Further,processor 1630 can process the extracted message to determine whichprecoding matrix to use for determining the beamforming weights.

Processors 1630 and 1670 can direct (e.g., control, coordinate, manage,etc.) operation at base station 1610 and mobile device 1650,respectively. Respective processors 1630 and 1670 can be associated withmemory 1632 and 1672 that store program codes and data. Processors 1630and 1670 can determine or detect interference, adjust IFHO thresholds ordata rates, switch access modes, boost transmit power, adjust pathlossedge targets, etc., as described.

FIG. 17 illustrates a wireless communication system 1700, configured tosupport a number of users, in which the teachings herein may beimplemented. The system 1700 provides communication for multiple cells1702, such as, for example, macro cells 1702A-1702G, with each cellbeing serviced by a corresponding access node 1704 (e.g., access nodes1704A-1704G). As shown in FIG. 17, access terminals 1706 (e.g., accessterminals 1706A-1706L) can be dispersed at various locations throughoutthe system over time. Each access terminal 1706 can communicate with oneor more access nodes 1704 on a forward link (FL) and/or a reverse link(RL) at a given moment, depending upon whether the access terminal 1706is active and whether it is in soft handoff, for example. The wirelesscommunication system 1700 can provide service over a large geographicregion.

FIG. 18 illustrates an exemplary communication system 1800 where one ormore femto nodes are deployed within a network environment.Specifically, the system 1800 includes multiple femto nodes 1810A and1810B (e.g., femtocell nodes or H(e)NB) installed in a relatively smallscale network environment (e.g., in one or more user residences 1830).Each femto node 1810 can be coupled to a wide area network 1840 (e.g.,the Internet) and a mobile operator core network 1850 via a digitalsubscriber line (DSL) router, a cable modem, a wireless link, or otherconnectivity means (not shown). As will be discussed below, each femtonode 1810 can be configured to serve associated access terminals 1820(e.g., access terminal 1820A) and, optionally, alien access terminals1820 (e.g., access terminal 1820B). In other words, access to femtonodes 1810 can be restricted such that a given access terminal 1820 canbe served by a set of designated (e.g., home) femto node(s) 1810 but maynot be served by any non-designated femto nodes 1810 (e.g., a neighbor'sfemto node).

FIG. 19 illustrates an example of a coverage map 1900 where severaltracking areas 1902 (or routing areas or location areas) are defined,each of which includes several macro coverage areas 1904. Here, areas ofcoverage associated with tracking areas 1902A, 1902B, and 1902C aredelineated by the wide lines and the macro coverage areas 1904 arerepresented by the hexagons. The tracking areas 1902 also include femtocoverage areas 1906. In this example, each of the femto coverage areas1906 (e.g., femto coverage area 1906C) is depicted within a macrocoverage area 1904 (e.g., macro coverage area 1904B). It should beappreciated, however, that a femto coverage area 1906 may not lieentirely within a macro coverage area 1904. In practice, a large numberof femto coverage areas 1906 can be defined with a given tracking area1902 or macro coverage area 1904. Also, one or more pico coverage areas(not shown) can be defined within a given tracking area 1902 or macrocoverage area 1904.

Referring again to FIG. 18, the owner of a femto node 1810 can subscribeto mobile service, such as, for example, 3G mobile service, offeredthrough the mobile operator core network 1850. In addition, an accessterminal 1820 can be capable of operating both in macro environments andin smaller scale (e.g., residential) network environments. Thus, forexample, depending on the current location of the access terminal 1820,the access terminal 1820 can be served by an access node 1860 or by anyone of a set of femto nodes 1810 (e.g., the femto nodes 1810A and 1810Bthat reside within a corresponding user residence 1830). For example,when a subscriber is outside his home, he is served by a standard macrocell access node (e.g., node 1860) and when the subscriber is at home,he is served by a femto node (e.g., node 1810A). Here, it should beappreciated that a femto node 1810 can be backward compatible withexisting access terminals 1820.

A femto node 1810 can be deployed on a single frequency or, in thealternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies can overlap with one or more frequencies used by a macrocell access node (e.g., node 1860). In some aspects, an access terminal1820 can be configured to connect to a preferred femto node (e.g., thehome femto node of the access terminal 1820) whenever such connectivityis possible. For example, whenever the access terminal 1820 is withinthe user's residence 1830, it can communicate with the home femto node1810.

In some aspects, if the access terminal 1820 operates within the mobileoperator core network 1850 but is not residing on its most preferrednetwork (e.g., as defined in a preferred roaming list), the accessterminal 1820 can continue to search for the most preferred network(e.g., femto node 1810) using a Better System Reselection (BSR), whichcan involve a periodic scanning of available systems to determinewhether better systems are currently available, and subsequent effortsto associate with such preferred systems. Using an acquisition tableentry (e.g., in a preferred roaming list), in one example, the accessterminal 1820 can limit the search for specific band and channel. Forexample, the search for the most preferred system can be repeatedperiodically. Upon discovery of a preferred femto node, such as femtonode 1810, the access terminal 1820 selects the femto node 1810 forcamping within its coverage area.

A femto node can be restricted in some aspects. For example, a givenfemto node can only provide certain services to certain accessterminals. In deployments with so-called restricted (or closed)association, a given access terminal can only be served by the macrocell mobile network and a defined set of femto nodes (e.g., the femtonodes 1810 that reside within the corresponding user residence 1830). Insome implementations, a femto node can be restricted to not provide, forat least one access terminal, at least one of: signaling, data access,registration, paging, or service.

In some aspects, a restricted femto node (which can also be referred toas a Closed Subscriber Group H(e)NB) is one that provides service to arestricted provisioned set of access terminals. This set can betemporarily or permanently extended as necessary. In some aspects, aClosed Subscriber Group (CSG) can be defined as the set of access nodes(e.g., femto nodes) that share a common access control list of accessterminals. A channel on which all femto nodes (or all restricted femtonodes) in a region operate can be referred to as a femto channel.

Various relationships can thus exist between a given femto node and agiven access terminal. For example, from the perspective of an accessterminal, an open femto node can refer to a femto node with norestricted association. A restricted femto node can refer to a femtonode that is restricted in some manner (e.g., restricted for associationand/or registration). A home femto node can refer to a femto node onwhich the access terminal is authorized to access and operate on. Aguest femto node can refer to a femto node on which an access terminalis temporarily authorized to access or operate on. An alien femto nodecan refer to a femto node on which the access terminal is not authorizedto access or operate on, except for perhaps emergency situations (e.g.,911 calls).

From a restricted femto node perspective, a home access terminal canrefer to an access terminal that authorized to access the restrictedfemto node. A guest access terminal can refer to an access terminal withtemporary access to the restricted femto node. An alien access terminalcan refer to an access terminal that does not have permission to accessthe restricted femto node, except for perhaps emergency situations, forexample, 911 calls (e.g., an access terminal that does not have thecredentials or permission to register with the restricted femto node).

For convenience, the disclosure herein describes various functionalityin the context of a femto node. It should be appreciated, however, thata pico node can provide the same or similar functionality as a femtonode, but for a larger coverage area. For example, a pico node can berestricted, a home pico node can be defined for a given access terminal,and so on.

A wireless multiple-access communication system can simultaneouslysupport communication for multiple wireless access terminals. Asmentioned above, each terminal can communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link can be established via a single-in-single-out system,a MIMO system, or some other type of system.

The various illustrative logics, logical blocks, modules, components,and circuits described in connection with the embodiments disclosedherein may be implemented or performed with a general purpose processor,a digital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but, in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Additionally, at least oneprocessor may comprise one or more modules operable to perform one ormore of the steps and/or actions described above. An exemplary storagemedium may be coupled to the processor, such that the processor can readinformation from, and write information to, the storage medium. In thealternative, the storage medium may be integral to the processor.Further, in some aspects, the processor and the storage medium mayreside in an ASIC. Additionally, the ASIC may reside in a user terminal.In the alternative, the processor and the storage medium may reside asdiscrete components in a user terminal.

In one or more aspects, the functions, methods, or algorithms describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software, the functions may be stored ortransmitted as one or more instructions or code on a computer-readablemedium, which may be incorporated into a computer program product.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable media that can be accessed by a computer. By way of example,and not limitation, such computer-readable media can comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, substantiallyany connection may be termed a computer-readable medium. For example, ifsoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc where disks usually reproducedata magnetically, while discs usually reproduce data optically withlasers. Combinations of the above should also be included within thescope of computer-readable media.

While the foregoing disclosure discusses illustrative aspects and/orembodiments, it should be noted that various changes and modificationscould be made herein without departing from the scope of the describedaspects and/or embodiments as defined by the appended claims.Furthermore, although elements of the described aspects and/orembodiments may be described or claimed in the singular, the plural iscontemplated unless limitation to the singular is explicitly stated.Additionally, all or a portion of any aspect and/or embodiment may beutilized with all or a portion of any other aspect and/or embodiment,unless stated otherwise.

What is claimed is:
 1. A method for mitigating interference in wirelesscommunications, comprising: detecting, at a first access point,interference from one or more devices communicating with one or moreserving access points other than the first access point; and increasing,at the first access point, a downlink transmit power over time based ondetecting the interference, wherein the downlink transmit power isincreased according to a boosting pattern in which the downlink transmitpower is boosted for a first duration of time and the boosting of thedownlink transmit power is increased for a second duration of time basedat least on detecting the interference after the first duration of time.2. An apparatus for mitigating interference in wireless communications,comprising: at least one processor configured to: detect interferencefrom one or more devices communicating with one or more serving accesspoints other than the apparatus; and increase a downlink transmit powerover time based on the detected interference, wherein the downlinktransmit power is increased according to a boosting pattern in which thedownlink transmit power is boosted for a first duration of time and theboosting of the downlink transmit power is increased for a secondduration of time based at least on detecting the interference after thefirst duration of time; and a memory coupled to the at least oneprocessor.
 3. An apparatus for mitigating interference in wirelesscommunications, comprising: means for detecting interference from one ormore devices communicating with one or more serving access points otherthan the apparatus; and means for increasing a downlink transmit powerover time based on the detected interference, wherein the downlinktransmit power is increased according to a boosting pattern in which thedownlink transmit power is boosted for a first duration of time and theboosting of the downlink transmit power is increased for a secondduration of time based at least on detecting the interference after thefirst duration of time.
 4. A non-transitory computer-readable medium formitigating interference in wireless communications, comprising: code forcausing a first access point to detect interference from one or moredevices communicating with one or more serving access points other thanthe first access point; and code for causing the first access point toincrease a downlink transmit power over time based on the detectedinterference, wherein the downlink transmit power is increased accordingto a boosting pattern in which the downlink transmit power is boostedfor a first duration of time and the boosting of the downlink transmitpower is increased for a second duration of time based at least ondetecting the interference after the first duration of time.
 5. Anapparatus for mitigating interference in wireless communications,comprising: an interference detecting component configured to detectinterference from one or more devices communicating with one or moreserving access points other than the apparatus; and a downlink transmitcomponent configured to increase a downlink transmit power over timebased on the detected interference, wherein the downlink transmit poweris increased according to a boosting pattern in which the downlinktransmit power is boosted for a first duration of time and the boostingof the downlink transmit power is increased for a second duration oftime based at least on detecting the interference after the firstduration of time.
 6. The method recited in claim 1, wherein the downlinktransmit power is increased to cause interference at the one or moredevices from which the interference was detected.
 7. The method recitedin claim 1, wherein the downlink transmit power is increased to cause aninter-frequency handover at the one or more devices from which theinterference was detected.
 8. The method recited in claim 1, furthercomprising lowering the downlink transmit power to an original levelduring a period between the first duration of time and the secondduration of time.
 9. The method recited in claim 1, wherein the boostingpattern groups the first duration of time and the second duration oftime into a cluster of bursts, and wherein the method further comprisesreturning the downlink transmit power to an original level for anextended time duration after a last burst in the cluster of bursts. 10.The apparatus recited in claim 2, wherein the downlink transmit power isincreased to cause interference at the one or more devices from whichthe interference was detected.
 11. The apparatus recited in claim 2,wherein the downlink transmit power is increased to cause aninter-frequency handover at the one or more devices from which theinterference was detected.
 12. The apparatus recited in claim 2, whereinthe at least one processor is further configured to lower the downlinktransmit power to an original level during a period between the firstduration of time and the second duration of time.
 13. The apparatusrecited in claim 2, wherein the boosting pattern groups the firstduration of time and the second duration of time into a cluster ofbursts, and wherein the at least one processor is further configured toreturn the downlink transmit power to an original level for an extendedtime duration after a last burst in the cluster of bursts.
 14. Theapparatus recited in claim 3, wherein the downlink transmit power isincreased to cause interference at the one or more devices from whichthe interference was detected.
 15. The apparatus recited in claim 3,wherein the downlink transmit power is increased to cause aninter-frequency handover at the one or more devices from which theinterference was detected.
 16. The apparatus recited in claim 3, furthercomprising means for lowering the downlink transmit power to an originallevel during a period between the first duration of time and the secondduration of time.
 17. The apparatus recited in claim 3, wherein theboosting pattern groups the first duration of time and the secondduration of time into a cluster of bursts, and wherein the apparatusfurther comprises means for returning the downlink transmit power to anoriginal level for an extended time duration after a last burst in thecluster of bursts.
 18. The non-transitory computer-readable mediumrecited in claim 4, wherein the downlink transmit power is increased tocause interference at the one or more devices from which theinterference was detected.
 19. The non-transitory computer-readablemedium recited in claim 4, wherein the downlink transmit power isincreased to cause an inter-frequency handover at the one or moredevices from which the interference was detected.
 20. The non-transitorycomputer-readable medium recited in claim 4, further comprising code forcausing the first access point to lower the downlink transmit power toan original level during a period between the first duration of time andthe second duration of time.
 21. The non-transitory computer-readablemedium recited in claim 4, wherein the boosting pattern groups the firstduration of time and the second duration of time into a cluster ofbursts, and wherein the non-transitory computer-readable medium furthercomprises code for causing the first access point to return the downlinktransmit power to an original level for an extended time duration aftera last burst in the cluster of bursts.
 22. The apparatus recited inclaim 5, wherein the downlink transmit power is increased to causeinterference at the one or more devices from which the interference wasdetected.
 23. The apparatus recited in claim 5, wherein the downlinktransmit power is increased to cause an inter-frequency handover at theone or more devices from which the interference was detected.
 24. Theapparatus recited in claim 5, wherein the downlink transmit component isfurther configured to lower the downlink transmit power to an originallevel during a period between the first duration of time and the secondduration of time.
 25. The apparatus recited in claim 5, wherein theboosting pattern groups the first duration of time and the secondduration of time into a cluster of bursts, and wherein the downlinktransmit component is further configured to return the downlink transmitpower to an original level for an extended time duration after a lastburst in the cluster of bursts.